The present invention relates to a technique for identifying an ink cartridge which supplies ink at an appropriate negative pressure to a recording head which ejects ink droplets in response to print signals.
An ink-jet recording device is usually configured so that an ink-jet recording head for ejecting ink droplets in response to print signals is mounted on a carriage which makes reciprocating motion in a direction of the width of a recording sheet, and so that ink is supplied from an external ink tank to the recording head. In the recording head of a small-size type, an ink storage container such as an ink tank or the like is detachably attached to the carriage. On the other hand, in the recording head of a large-size type, the ink storage container is set on a frame or casing of the recording device, and connected to the recording head through an ink supply tube.
The ink tank mounted on the carriage is usually configured so that a porous member such as sponge or the like is contained in the ink tank and impregnated with ink in order to reduce the change of pressure stemming from waving of ink or the like caused due to the reciprocating motion of the carriage.
Even in the case where the recording head is supplied with ink from a large-capacity ink bag, set on the frame, through the ink supply tube, ink is supplied to the recording head through a sub-tank having a damping function for preventing the change of ink pressure due to the motion of the carriage, in order to prevent the change of ink pressure from being caused by the bending of the tube due to the reciprocating motion of the carriage.
Hence, the former has a problem that the size or weight of the ink tank is increased by the volume of the porous member contained in the ink tank in comparison with the volume of ink capable of being contained in the ink tank. The latter has a problem that the recording device is complicated in structure because a mechanism is required for preventing the change of ink pressure owing to vibration.
Both recording head and ink have been further improved for the purpose of improving print quality, and ink adapted to the recording head is designated by the maker.
On the other hand, because the ink cartridge is formed as a rectangular parallelepiped container from the point of view of the structure, or the like, of the recording device, there is a problem that the ink cartridge adapted to the recording device can be hardly identified and may be selected by mistake.
To solve the problem, protruded portions are formed in an ink cartridge holder of the recording device, and recessed portions are formed in the ink cartridge so as to be adapted to the protruded portions. That is, an ink supply needle passes through an ink supply port only when the protruded portions fit into the recessed portions.
If the weight of the ink cartridge, that is, the capacity thereof is reduced to make high-speed printing possible, there is however a problem that the number of kinds of recessed portions allowed to be formed in the narrow bottom portion of the ink cartridge is limited.